PATNA, June 14 -- A notorious extortionist was injured in a joint operation carried out by the Vaishali police and the Special Task Force (STF) in the Digghi Kala locality under Sadar police station limits on Friday. His associate was also arrested during the operation, police said. The injured extortionist was identified as Rajiv Mali (40), a resident of Digghi Kala. He was first taken to Sadar Hospital and later referred to Patna Medical College and Hospital (PMCH) for better treatment. No police personnel were injured in the encounter, said Vaishali Superintendent of Police (SP) Lalit Mohan Sharma....